Electric-arc lamp.



No. 867,544. PATENTED 0011,1907.

E. P. WINFIELD. ELECTRIC ARC LAMP.

APPLICATION FILED IAB.14, 1905.

in: Namus zrzns cm, Msummrm, n. c

EDWARD FRANKLIN WINFIELD, OF LOS ANGELES, CALIFORNIA.

ELECTRIC-ARC LAMP.

Specification of Letters Patent.

Patented Oct. 1, 1907.

Application filed March 14,1905. Serial No. 250,102.

To all whom it may concern:

Be it known that I, EDWARD FRANKLIN WINFIELD, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented certain new and useful Improvements in Electric-Arc Lamps, of which the following is a specification.

My improvement relates to the class of electric arc lamps and more particularly to the manner of supporting and adjusting the upper or movable carbon, the lower or stationary one being fastened to the lamp frame or support, in any usual manner.

The invention is illustrated in the accompanying drawings, in which I Figure 1 is a side elevation of my improved lamp with reflector attached; Fig. 2 is a front elevation of the same with reflector removed; Fig. 3 is a horizontal section of same on line rc-rc of Fig. 1; Fig. 4 is an enlarged broken detail of my movable carbon regulating and detaining device.

The style of lamp here shown is one best adapted for photographic purposes, the frame work being in this case supported upon a suitable floor stand (not shown in drawing) and the lamp having a reflector serving to strongly focus or project the light upon the object. It is obvious that any suitable frame can be used to mount the carbons, but the one here shown will fully illustrate a practical device.

Referring to the drawings 1 and 2 are vertical posts or pillars held together by insulated plates or brackets 3, 4, and 5 each of which is secured at its rear edge to the posts and extends forward with the front edge for the reception of the other parts of the lamp. The brackets 3 at their base also support the socket 6, in which is adj ustably fastened the lower or fixed carbon electrode 7, in any usual manner, as by a thumb screw 8. The upper bracket plates 4-and 5 carry or support between them the solenoid 9, within which the upper carbon electrode 10 works. The upper end of this electrode 10 is set within an expansible socket or thimble 11, (Fig. 1) having an upwardly extending projecting rod 12 passing outwardly beyond the top of the solenoid 9 and terminating in a binding post 13, the circular base 14 of which is of larger diameter than the central opening 15 of the solenoid, so that at no time can it drop beyond contact with the upper face of said solenoid, thus preventing the upper carbon from dropping down upon socket 6, and being destroyed while in circuit in case the lower carbon had accidentally fallen out or had been carelessly olni tted.

The solenoid core is composed of an upper hollow section 16 attached to the solenoid spool, and a lower movable and corresponding solenoid core 17, within both of which may play the carbon electrode 10, (Fig. 1). The lower member 17, of the core has a horizontally projecting arm 18 which, immediately around the base of the core 17, preferably forms a flange or cap of greater diameter than the opening in the solenoid spool. From the outer extremity of this arm 18 projects downwardly a threaded rod 19 having a circular headed are adjusting nut 20, upon which rests the clutching or clamping plate 21. This plate is bent at or about one-third of its length (Figs. 1 and 4) at a point a forming a horizontal part b and an inclined part I). Just at the commencement of the inclined part b a hole 22 is drilled slightly larger in diameter than the diameter of the carbon electrode and this hole having been drilled before bending the plate 21, it will be seen that the said hole lies in the plane of the bent portion b As the normal position of this plate is as shown in Figs. 1 and 4 it will be seen that being supported at its highest extremity by the threaded rod 19 and resting upon the globular surface of the are adjusting screw 20, a slight change of the position of clutch 21 will allow the carbon electrode 10 passing through the opening 22 to slip by its own gravity through this opening, but it will be prevented from slipping upon the carbon in an upward direction owing to the clamping effect produced by the sharp edges 0, e the upper and lower faces respectively of the plate 21 (Fig. 4) engaging the carbon.

Depending from the lower head of the solenoid spool 9, and immediately over the outer horizontal end of the plate 21 is a small rod 23, around which is coiled a slight spiral pressure spring 24. This spring extends below the end of the rod 23 and rests upon the upper surface of the plate 21, (Fig. 1) and keeps this latter in gentle but firm contact around the carbons 10 when operating and prevents its sudden l0os ening of its hold on the carbon, obviating jar, It also prevents of any lateral or axial or rotary movement of the plate that may be necessary to cause it to firmly grasp the carbon when the solenoid is drawn upward. At either side of the plate 21 are two rods 25, 26 (Fig. 3) depending also from the bracket 5 forming part of the lower head of the solenoid 9. These rods carry a guide 27 through which loosely passes the carbon 10; by this means the latter is kept in a true vertical position.

A metallic or other reflector 28 is fastened to the main rods 1, 2, by a cross bracket 29, and 30 is a globe inclosing the carbons and is of the usual type. 31 is an electric switch button also of the usual type.

An insulated flange 32 projects from below the bracket 3 of the apparatus and is pivoted to the flattened projecting head 33 of the supporting rod 34. This latter is fastened to the wall or floor in any suitable manner to support the whole apparatus in a Yuan and rigid position. The quadrant is secured by means of the butterfly nut 35 so that the angle of deflection of the light can be changed as desired, allowing the concen trated rays to be projected by reflecto nupon the object and at the spot required. a

The electrical connections are as follows. The main port the core and Wire 37 is insulated end of this hollow rod is from there carried to the switch button 31, by the auxiliary insulated wire 40. From the switch it is now carried to the binding post 41 by the insulated wire 42. This binding post is attached directly to the metal lower plate bracket 3 of the lamp frame which transmits this end of the current to the lower electrode 7, the latter being in contact with the metalsocket 6 forming part of the bracket 3. Connection may or may not be made by a very light wire 43 between the top of the upper electrode and the binding post 44 attached to the upper metallic plate bracket 4. This serves merely as a precautionary measure.

The operation of my improved arc lamp is as fol lows: As the current is turned on through the closing of the switch 31, it will pass into the solenoid, magnetizing the fixed upper hollow iron core 16, which will immediately attract the corresponding loose hollow core 17. Therefore the parts 16 and 17 freeze or become united as one magnetic core, preventing part 17 from jumping 'up and down and causing flickering. Thus if lamps are installed where feed wires areat times overloaded, as by throwing motors, etc.,

in circuit, and so varying the strength, part 17 would move up and down, but as it freezes to part 16, such motion is impossible so long as there is enough voltage to force its way across the arc. Of course, when lamps are installed, they are adjusted by screw 20. The rod 23 and spring 24 take the place of the dash pots, commonly used in arc lamps. When lamps are provided with dash pots and the dash pots get out of order, as they do quite frequently, the solenoid keeps jumping up and down at a terrific rate. if the solenoid goes up without resistance from dash pot, it throws or pulls the carbon out of the circuit, causing circuit to make and break. With my lamp I have improved on the above by using the rod and spring, or only the rod 23 which cannot get out of order as a delicate dash pot can. The core 17 clamps or bites upon the electrode 10 and carries it upward, separating its lower point from contact withthe upper point of the lower electrode 7 and establishing the are. As the carbons are consumed, especially the upper one, the increasing separation of the electrodes causes a lessening of the amount of current passing through the solenoid spool, thereby lessening as well its power to hold suspended the lower hollow core carrying the upper carbon electrode, which dropping downwards causes the central portion of the plate or clutch 21 to engage with the guide 27 and be tilted or rocked thereon which changes the position of the clutch so as to allow the carbon to slip through the opening 22 sufficiently to take up the burned portion of the same, restoring the light are to its normal state,

and connects by wire 39 The reason for this is that and again allowing the full amount of current to flow through the lamp and solenoid which again will supcarbon in the proper position by I lifting the same within the opening 15 of the solenoid spool. These movements are effected so instantaneously and sosmoothly that no perceptible diminution of strength or flickering in the light are is perceptible; theusual tendency for the upper electrode to vibrate and the light in consequence to sputter is obviated by the already described peculiar property of the carbon supporting plate 21, allowing the carbon to move through its own gravity, only when, and

immediately upon being released through the dropping of the plate 21. Any jar that might take place owing to the action of the solenoid in attracting upwardly the plate 21, and the subsequent slipping down of the electrode is neutralized and obviated by the light coil spring 24 which acts with sufiicient pressure at all times to insure close contact of the biting edges 0, c of the opening 22 in the plate 21 upon the electrode 10. And as the core 17 is rotatable within the solenoid the end of the arm and plate 21 may have a slight lateral movement, which, with the free movement, laterally and vertically, of the other end of the plate 21 that is secured by the arrangement of the spring 24, permits of a slight axial movement of the carbon and prevents any possibility of the plate binding or becoming so fastened that it can not release the carbon 10 and permit it to fall into contact with the other carbon and thereby reestablish the circuit. This as will be seen results in an arc lamp of simple construction, of few parts, and which produces a steady, constant and reliable light. This is of the utmost importance in all cases, and especially in photographic work Where the light value must be constant in order to be effective. I 7

Having thus fully described my invention what I claim as new and desire to secure by Letters Patent is: i

1. In an electric are light, vertical supports, insulated brackets thereon, a solenoid in the upper brackets, and a carbon support in the lower bracket, rods depending from the lower one of the upper brackets, a perforated guide carried by two of said rods, a spring on the other rod, the end of which extends below the end of said rod, an arm on the solenoid, the free end of which is provided with a depending screw threaded rod adapted to normally stand opposite said spring and its rod, a perforated clutch plate upon the screw threaded red at one end and resting against said spring at the other with its intermediate portion adapted to engage with said guide, and a nut on the screw threaded rod. 7

2. In an electric are light two vertical supports, insulated brackets secured at their rear edges thereto, a solenoid between the front edges of the upper brackets and a carbon holder in the forward edge of the lower bracket, means connected with the solenoid for holding and feeding a carbon, a cross bracket on said supports intermediate their ends, and a reflector on the bracket with its forward end extending beyond the front edges of said brackets.

In testimony whereof I have aflixed my signature, in presence of two Witnesses, this sixth day of February, 1905.

4 EDWARD FRANKLIN WINFIELD.

Witnesses:

W. P. COMINGON, R. J. CRAFT.

thoroughly 

